An infusion pump may be used to infuse fluids, medication, or nutrients into a patient's body or circulatory system. An infusion pump is generally used intravenously, although subcutaneous, arterial and epidural infusions are occasionally used. Infusion pumps can reliably administer fluids in ways that would be impractically expensive or unreliable if performed manually by nursing staff. For example, infusion pumps can administer 1 mL per hour injections (too small for a drip), injections every minute, injections with repeated boluses requested by the patient up to the maximum number per hour allowed (e.g. in patient-controlled analgesia), or fluids whose volumes vary by the time of day.
As infusion pumps can also produce quite high but controlled pressures, the pumps can inject controlled amounts of fluids subcutaneously (beneath the skin), or epidurally (just within the surface of the central nervous system—a very popular local spinal anesthesia for childbirth).
Conventional infusion pumps rely on disposable infusion sets to link the pump system to an infusion site. These sets generally have a length of tubing between both ends to accommodate the patient's changes to wear position, pump maintenance and programming and to facilitate changing of the catheter system. As pump systems gradually reduce in size and complexity, the tubing becomes tangled as a result of its length making the pumps difficult to use and uncomfortable for the patient.